According to the prior art, apparatuses for cutting swathes or pieces of fabric, or similar material, in appropriately shaped portions, in particular for the manufacture of clothes or other clothing items, comprise a single area for the cutting of said pieces, in correspondence whereto the cutting into shaped portions is effected by means of a hack sawing machine, suitably actuated along the piece.
In such known machines, said material is supported on a sort of yielding support plane, which is defined by means of appropriate supporting bristles, which allow said hack sawing machine to extend beyond the plane defined by the two-dimensional piece, inserting themselves between the aforementioned supporting bristles.
The use of such a yielding support leads to a non perfectly horizontal disposition of the material and to a retention thereof that is not effective in every point, with consequent cutting inaccuracies on the part of the hack sawing machine.
In these known machines, the pieces, once cut, are manually removed from the cutting area. To obtain an acceptable productivity of such machines, work is conducted simultaneously on a certain quantity of pieces (a few tens, for instance 40–50 pieces), of rectangular or square shape, which are stacked onto the bristle support and held thereon by means of a vacuum opportunely applied on the side of said bristle support. Once the pieces are cut, they are then collectively and manually removed by assigned personnel. To assure a removal intervention that is as rapid as possible, however, an excessive number of personnel is employed, which personnel cyclically perform appropriate manual operations for the removal of the cut pieces and then remain idle between a removal and the next. The cost for such excessive manpower negatively influences the cost of production of the item. Moreover, the manual removal operation is slow and it also slows down the start of a subsequent cutting phase.
Also elaborate, slow and costly is the preparation of the stack of pieces, which entails the disposition of said pieces one on top of the other, alternated with paper sheets whose function is to stiffen and support the pack or plurality of superposed pieces of fabric to be cut. To the pieces is also superposed a plastic film that allows the aspiration and retention of the pack on the bristle carpet.
The use of such a vacuum retention system for the pieces also leads to the construction of complex, costly machines which absorb a considerable quantity of energy.
The aspiration system for the pieces, moreover, is noisy and gives off heat to the space housing the cutting machine, creating corresponding temperature control problems.
Moreover, such a manner of operating with superposed pieces necessarily forces to cut pieces in portions that are all identical to manufacture clothes which are necessarily of the same size. Because the stack of pieces to be cut is sustained on a yielding (bristle) support, the drawback of a differentiated cut from piece to piece arises, and is particularly accentuated between the pieces lying at the top and those that are at the bottom of the stack to be cut. Thus, the drawback emerges of clothes produced from different pieces which, although they should be of the same size, do not at all have the same geometric dimensions.
Moreover, in such known machines, because pieces are used having predefined quadrangular shape which are then stacked and cut collectively, a certain number of unusable scrap portions are necessarily present in each piece, in particular in correspondence with the peripheral areas of said pieces. This material cannot be used in any way at all and hence it must be scrapped, leading to material wastage and costs for manufacturing companies.
According to another disadvantageous aspect of prior art machines, mutually adjacent fabric portions are cut according to cutting lines that are close to, but distinct from, one other. The fabric present between said close cutting lines becomes scrap material, thereby considerably contributing to the excessive production of scrap material in said prior art machines.
In some known machines, the use of a hack saw forces to start cutting the pieces from an edge thereof. The cut of the piece into related portion cannot be planned freely but must take into account this constraint relating to the starting point of the cut. Other known machines, of a more complex kind, instead make use of an appropriate drilling head, which allows to start the cut in any point inside the surface of the pieces, which drilling head is added to the aforementioned hack saw, making the corresponding machine excessively complex.